Process of and apparatus for making battery jars



J. E. PERRAULT AND C. H. ROPER.

PROCESS OF AND- APPARATUS FOR MAKING BATTERY JARS.

APPLICATION FILED FEB. 8, 192],

1,412,962w PatentedApr. 18, 1922.

W W ATTORA/EYS UNITED STATES PATENT} oFFicE.

JOSEPH E. PERRAULT, OF WATER-TOWN, AND CHARLES H., ROPER, OF BELMONT, MASSACHUSETTS, ASSIGNORS T HOOD RUBBER COMPANY, OF WATERTOWN, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS. I

PROCESS OF AN D APPARATUS FOR MAKING BATTERY ARS.

To allwhom it may concern:

Be it known that we,'JosEPrI E.'PERRAULT and CHARLES H. RorER, citizens of the United States, and residents of Watertown', Massachusetts, and Belmont, Massachusetts, re-

spectively, have invented certain new and useful Improvements in Processes of and being overlapped and its bottom edges being lapped over the bottom, the edges being skived where necessary, and the whole rolled down to secure propershape and joint adherence. Thereafter the rubber vulcanizing compound is vulcanized, and the completed article is stripped from the mandrel.

A large percentage of cells produced by methods heretofore employed have proved to be defective, by reason of the expansion of gases between the sheets and walls of the mandrel, cgusing warped or blistered cell walls, and also by reason of difliculty in stripping the completed cell from the former.

The present invention aims to avoid these objections and comprises the novel method of procedure and core or mandrel for carrying out such process as hereinafter'described and particularly defined by the appended claims.

Our preferred former is illustrated in the accompanying drawings in whichthe figure 1s a perspective view thereof.

Referring by reference characters to this 4 drawing, the former or mandrel, which is indicated as a whole at A, and which may be constructed of any suitable material, is preferably made hollow and of general exterior dimensions corresponding to the interior dimensions of the cell to be formed thereon.

The bottom of I the mandrel, or portion which is utilized to form the cell bottom 'or base, is provided with transverse grooves A, which are designed to receive and sup- Specification of Letters Patent. Patented Apr. 18, 1922.

Application filed February 8, 1921.

Serial No. 443,346.

port during vulcanization the material forming the ribs or cross bridges of the cell base.

In the making of the cell a preformedand partially vulcanized base may be used having integral ribs 01' bridges or a hand made base may be used, in which event strips of bridge forming material are first placed in the grooves and thereafter the bottom forming layer applied. The wall stock is then wrapped around the mandrel, enough of the wall stock extending beyond the base to allow for trimming and turning down in order to form the base seam and unite the base and walls. 4 The wall stock is thereafter rolled down with a suitable roller, the wrapping and rolling process causing the stock to hug the mandrel.

With the use of plain surfaced mandrels as heretofore, we have found it impossible to prevent the entrapping of more or less air between the wall stock and mandrel which, when heat is applied, produces blisters or warped'walls.

We have discovered that it is not necessaryto support the stock evenly over the entire surface of a plain smooth faced mandrel as has heretofore been believed necessary, but that a perfect cell having smooth interior and exterior walls may be formed by applying the wall stock to a mandrel having a surface which supports the stock upon a plurality of isolated portions.

Such isolated portions may consist ofi longitudinally disposed ribs A which, in the mandrel shown in the drawing, are formed by providing the mandrel with longitudinal flutes or grooves L. Obviously, however, the walls of the former would be of skeleton formation, as the manner in which the raised stock supporting surfaces are con-' nected is immaterial. When the stock is wrapped and rolled upon such a mandrel it is supported upon the raised surfaces and numerous intervening underlying channels are provided which communicate with the atmosphere and allow the ready escape of air and gases caused by the vulcanizing heat.

We have further found that with such a mandrel the stripping of the completed jar or cell is an easy matter, as the cell walls are in contact with the mandrel surface for only a minimum area and the frictional reistance is greatly reduced. The danger of breakage is thusly eliminated. We find that removal is further facilitated by giving the walls adjacent the bottom of the mandrel a sli ht taper, as indicated at (if.

aving thus described our invention, what we claim is:

1. The hereindescribed method of forming vulcanized battery jars which consists in applying sheets of unvulcanized material to a former having its surfaces provided with a plurality of raised portions for supporting said sheets spaced from the remaining portions of the former, vulcanizing the article, and then stripping it from the former.

2. The hereindescribed method of making vulcanized battery cells which consists in applying sheets of unvulcanized material to a former, subjecting the same to a vulcanizing heat, and simultaneously venting the space between the former and cell walls, and finally stripping the article.

3. The hereindescribed method of making vulcanized battery jars which consists in assembling sheets to form the jar walls and bottom and supporting the side wall sheets, during such assembling, at a plurality of isolated places, vulcanizing said sheets while so supported, and thereafter removing the article from the support.

4. The hereindescribed method of making vulcanized battery jars which consists in assembling sheets to form the jar walls and bottom and supporting the side wall sheets, during such assembling, at a plurality of parallel lines, vulcanizing said sheets while so supported, and thereafter removing the article from the support.

5. A core or mandrel for mal ingvulcanized battery jars having its walls provided.

JOSEPH E. PERRAULT. CHARLES H. ROPER. 

